bisecting fixing commit since 2762b48e9611529239da2e68cba908dbbec9805f
building syzkaller on 63631df1539816bc62c7be40779c5f3e23b23b2f
testing commit 2762b48e9611529239da2e68cba908dbbec9805f with gcc (GCC) 8.4.1 20210217
kernel signature: 953ba8065364e3429167d939139fa3355559e994be1f85c8723fbfa27b30fca1
all runs: crashed: general protection fault in hsr_dev_change_mtu
testing current HEAD 29c52025152bab4c557d8174da58f1a4c8e70438
testing commit 29c52025152bab4c557d8174da58f1a4c8e70438 with gcc (GCC) 8.4.1 20210217
kernel signature: 96f37cd592e69b7588373f0f33859bb37166a7634540c19c491802511938eaeb
all runs: crashed: general protection fault in hsr_dev_change_mtu
revisions tested: 2, total time: 21m5.79404608s (build: 14m5.91490664s, test: 6m4.718075159s)
the crash still happens on HEAD
commit msg: Linux 4.14.221
crash: general protection fault in hsr_dev_change_mtu
Bluetooth: hci4 command 0x0419 tx timeout
Bluetooth: hci2 command 0x0419 tx timeout
bond0: The slave device specified does not support setting the MAC address
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 1 PID: 9701 Comm: syz-executor.2 Not tainted 4.14.221-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff888098852380 task.stack: ffff88809ee20000
RIP: 0010:hsr_dev_change_mtu+0x87/0xb0 net/hsr/hsr_device.c:149
RSP: 0018:ffff88809ee26d08 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff888098c70c40 RCX: 1ffff1101310a57f
RDX: 0000000000000002 RSI: 0000000000000002 RDI: 0000000000000010
RBP: ffff88809ee26d28 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000028 R11: ffff888098852380 R12: ffff888098c71700
R13: 00000000000005dc R14: 0000000000000000 R15: ffff888098c70c40
FS:  00007f1992cd2700(0000) GS:ffff8880ba700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0a1e94e740 CR3: 0000000099af4000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __dev_set_mtu net/core/dev.c:6875 [inline]
 dev_set_mtu+0x1d3/0x3e0 net/core/dev.c:6910
 bond_enslave+0x672/0x4b40 drivers/net/bonding/bond_main.c:1507
 do_set_master net/core/rtnetlink.c:1961 [inline]
 do_set_master+0x163/0x1f0 net/core/rtnetlink.c:1936
 do_setlink+0x93e/0x2c80 net/core/rtnetlink.c:2098
 rtnl_newlink+0xeda/0x1610 net/core/rtnetlink.c:2660
 rtnetlink_rcv_msg+0x34c/0x9e0 net/core/rtnetlink.c:4316
 netlink_rcv_skb+0x12f/0x3b0 net/netlink/af_netlink.c:2433
 rtnetlink_rcv+0x10/0x20 net/core/rtnetlink.c:4328
 netlink_unicast_kernel net/netlink/af_netlink.c:1287 [inline]
 netlink_unicast+0x40b/0x610 net/netlink/af_netlink.c:1313
 netlink_sendmsg+0x639/0xbe0 net/netlink/af_netlink.c:1878
 sock_sendmsg_nosec net/socket.c:646 [inline]
 sock_sendmsg+0xac/0xf0 net/socket.c:656
 ___sys_sendmsg+0x625/0x920 net/socket.c:2062
 __sys_sendmsg+0xc1/0x140 net/socket.c:2096
 SYSC_sendmsg net/socket.c:2107 [inline]
 SyS_sendmsg+0xd/0x20 net/socket.c:2103
 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x465b09
RSP: 002b:00007f1992cd2188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000000000056c008 RCX: 0000000000465b09
RDX: 0000000000000000 RSI: 0000000020000600 RDI: 0000000000000005
RBP: 00000000004b069f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c008
R13: 00007ffc83fd3a3f R14: 00007f1992cd2300 R15: 0000000000022000
Code: 38 02 00 00 31 c0 5b 41 5c 41 5d 41 5e 5d c3 e8 50 a2 71 fa eb e7 49 8d 7e 10 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 75 1c 49 8b 7e 10 ba 06 00 00 00 48 c7 c6 e0 12 72 
RIP: hsr_dev_change_mtu+0x87/0xb0 net/hsr/hsr_device.c:149 RSP: ffff88809ee26d08
---[ end trace 78a1508bbe27f23a ]---